Perhaps without meaning to, the World Biodiversity Forum conducted something of an experiment in behavioural science this week.

The Forum organisers decided to only provide vegetarian and Vegan food at the meeting in Davos, Switzerland, as a tip of the hat to reversing the environmental impact meat production has on climate change and biodiversity. It is not the first scientific conference to do something like this: last year’s Global Land Programme’s Open Science meeting in Bern offered (quite delicious) waste food.

So, before the Forum dinner on Wednesday night – vegetable curry, beetroot salad, gnocchi and roast veg etc – people were told to ask specifically if they wanted meat. “I ordered meat,” said one man in the line to the waiter, in a reversal of the vegetarian/Vegan plight of having to request their meal on advance.

At least one of the scientists present saw the behavioural impact of what had happened.

“Good example of nudging behaviour change by changing the default,” tweeted Melissa Marselle, an environmental psychologist at the German Centre for Integrative Biodiversity Research.